Method and apparatus for purifying camphor



Sept. 18, 1923. 1,445,377

J. E. CRANE ET AL METHOD AND APPARATUS FOR- P URIFYING' CAMPHOR Filed March 23, 1918 5 Shees-$heet 1 A TTORNE Y Sept. 18, 1923. 1,468,377

J. E. CRANE ET AL.

- METHOD AND APPARATUS FOR PURIFYING CAMPHOR Filed March 23, 1918 5 Sheets-Sheet 3 Sept. 18 ,1923. I 1,468,377

Y .J. E. CRANE ET AL METHOD AND APPARATUS FOR PURILFYING CAMPHOR Filed March 23; 1918. 5 Sheets-Sheet 5 TTOR/VE Y Sept. 18 1923.

J. E. CRANE ET AL METHOD AND APPARATUS FOR PURIFYING CAMPHOR Filed March 23, 1918 5 Sheets-Sheet 4 I "1101, "nu",

, lllilllllln K 6 ATTORNEY 1,468,377 J. E. CRANE ET AL METHOD AND APPARATUS FOR PURIFYING CAMPHOR Sept. 18 ,11923;

Filed March 23, 1918 5 Sheets-Sheet 5 0'7 INVENTOR A & ,9

4 W ATTbkNfi "Patti fiept. 18,1923.

than v Filtmanna n. c am: EVABTS e.

LOOMIS, or NEWARK; new

smear, assrouoas 1 -E. L'DU FONT DE NEMOURS AND COMPANY, OE WILMINGTON, DELAWARE, A COB,-

M'ETHOIS. AND APPARATUS FOR PURIFYING CAMPHOB.

Application filed March 23, 1918. Serial No. 324,134.

To all whom it may concern: I

Be it known that JASPER E. CRANE and 'EVARTS G. LooMIs, of Newark, in the county of Essex andin the State of New Jersey, haveinvented a certain new and useful Improvement in Methods and Apparatus for I Purifying Camphor, and do hereby declare that the description thereof.

The invention has for an object to provide a method of treating camphor, so as to re-' move objectionable impurities from the same.

' Another object of the invention is to pro-' vide an apparatus in which such process may be carried out to purify large quant1t1es of camphor expeditiously and at low cost.

Further objects and advantages if the invention will appear from the detailed description thereof contained hereinafter, in which we have disclosed a specific form of apparatus and method of operation, Which apparatus and method of operation are, however, to be considered merely as illustrative of the principle of the invention. In the by means of which our drawings Fig. 1 is a side elevation of an apparatus invention may be carried out; A

Fig. 2 isan end elevation of the same. Fig. 3 is a vertical section of the pur fier shown in Figs. 1 and 2.

plan views respectively plates preferably used inthe purifier shown.

Fig. 6 is a plan view partially in section of the condenser shown in Figs. 1 and 2.

Fig. 7 is a section on line 7-7 of Fig. 6 looking in the direction of the arrows.

Fig. 8 is a section on line 8-8 of Fig. 7 Fig. 9 is a section on line 99 of Fig. 7. Fig. 10 is a vertical section showing in detail a preliminary cooler which may be used in connection with the condenser; and

Figs. 11 and 12 are respectively a longitudinal section and end view of a preferred form of baking chamber.

p 'In the drawings, 1 represents a preferred form of baking chamber, of which any desired number may be employed in the apparatus, which chambers are preferably sup-.

orted in inclined position by any suitable ramework, as shown in Figs. 1 and 2. Bake ing chamber 1 (Fig. 11) maybe made of v of the chamber a cover llowing is a full, clear, andexact steel or other suitable metal, and may be lined with any suitable material not subject to attack by camphor. To permit charging 4 is provided, held 1n place in any suitable manner as by wing nuts 5. The baking chamber is heated suitably, for example, by means of a jacket 6, through which heated oil from a circulating system later to be described, is passed. An

outlet' such as pipe 7 leads from chamber 1, such outlet being shown as controlled by valve 10 located therein and provided with an operating handle 11.

The outlet ing chambers 1 are shown as connected. to a header 8 which preferably leads, through pipe 9 to purifier 2, an element of especial importance to certain aspects of the present invention. The passageway through pipe 9 to purifier 2 is controlled by a valve 12, (Fig. 3), having an operating handle 13, and arms 13 adapted to remove solidified camphor from the bottom of the purifier when the valveis rotated. The purifier 2 may be of any desired shape, but preferably consists of a cylindrical vessel 2*, having a conical bottom 2*, and a removable to cover 2 to permit access to the same. ne or more pans such as 15are supported in the vessel 2 between inlet pipe 9 and outlet pipe 14: thereof, such pans providing a plurality of troughs 16, (Fig. 4) separated by spaces 17 and 18. Baffle plates 16 are located above the pans 15 and are shown as having inverted troughs 16 extending into troughs 16, and the latter are filled with a liquid such as camphor, through which any gases or vapors necessarily must pass in being led through the purifier. If desired, a further pipes 7 from the several bakoutlet opening 25v and pipe 23 may be provided, but the closed by disc 24, unless it be desired to divert the purified gases or vapors from the remainder of the apparatus; The purifier 2 is maintained at proper temperature, for instance. by a coil of pipes 2 which are preferably included in a heated oil circulating system later to be described. A mica window W may also be provided for convenience in watching the operation in the purifier.

As shown, a pipe 26 leads from outlet opening 14-, and preferably extends, as at passage through such pipe 29, (Fig. 10), within the interior of a preliminary cooler 30, which cooler may be cooled by the air, or artificially if desired.

Preliminary cooler 30 is shown as mounted upon a condenser 3, a passagewayJ 31 bein provided between thetwo mem ers As own particularly in Figs. 6 and 7 the condenser 3 p'erferabl consists of an elongated casing 32 within which may rotate two screw conveyors 34, s'upported by means such as bearings 34 and 34 in the casing. The spiral blades 35 of the conveyors are preferably located in staggered relation to each other, such blades substantially filling the space within the casing 32, as shown in Fig. 8, and the two conveyors 34 are rotated in the embodiment shown, by means of worm gears 36 which engage a worm 36- upon shaft 78. Theoutlet of the condenser 3 to which the camphor is advanced is shown at 37.

We have provided the followin pooling. etails of.

system for the condenser, the which, however, may be widely varied. A pipe 38 containing cooling water, is connected by means such as pipes 40, 42 and 43 (Fig. 8), with a water jacket 41 located beneath the condenser casing 32. A similar water jacket 45 is shown as provided above such casing, and connected to jacket 41 through pipes 44 and 46; from jacket 45 the cooling water is led through p pes 47, 48, 49 and 51, to an exhaust pipe 52. The interiors of screw conveyors 34 are supplied with cooling water from pipe 38, by means such as pipe 53, leading through pipes 54, 55, 56, 58 and 59, to receiving chambers 5 such as are shown respectively adjacent the bearings 34 of the screw conveyors 34. From chamber 57 the cooling water preferably passes through an annular space 60 in a neck 60 of the screw conveyor 34, and thence to the hollow interior 62 of the body ortion of the screw. The water thus flows the full length of the interior of such body portion, and back through the end 63 of a pipe 64, which serves to conduct the water to a fixed pipe 65, from which it is conducted to exhaust pipe 52, by means of pipes 67, 68 and 69 (Fig. 9). In order to cool bearings 34, we have provided means such as pipes 70 and 71 which lead from pipe 38 to a chamber 71 within'such bearing, and pipes 72 and 73 which are connected to ex haust pipe 52.

The means by which baking chambers 1 and purifier 2 are heated, is not essential to the invention, but such heating may be conveniently brought about bymeans of a heated oil circulating system as follows :-A reservoir R is provided, which is connected by pipe 81, which leads through electric heaters 82, to an oil pump P, a valve V being pm vided so that the oil supply in the can be shut off from the reservoir if desired.

from pipe 85 b amass? From the pump'P the oil is preferably delivered to a receiving chamber 84, from which itpasses through suitable piping to the various apparatus to be heated. Piping 85 preferably leads from chamber 84, and

. is connected to the baking chambers 1 by means of'fl pipe 86 and branch pipes 87,

, leading respectively to the difierent bakin chambers 1. Return pipes 89-may exten from the several baking chambers 1 to the pipe 91 which latter is shown as connected to pipe P. Valves 88 and 90, located respectively in pipes 87 and 89 control the flow of oil to the different baking chambers. Heating oil 81 so as to lead the oil back to pump is also shown as supplied to the purifier 2 means of a pipe 91*, leading through coil 2 to a ipe 92, which latter is shown as connecte to pipe on the low pressure side of a valve 93 located therein. Flow of oil to the purifier is controlled bymeans such as a valve 94 located in pipe 91*. Header 8 is shown as also heated by pipe 95 extending therethrough from pipe 85, and leading back to pipe 91.

In order that there will always be sufficient pressure to force the oil through the heating system, and also in order that overflow of the oil may be provided for in case the amounts supplied by the pump should be more than can be taken care of upon the shutting off of the valves, inthe embodiment shown a standpipe 96 (Fig. 2) is provided, which is connected by pipe 96 to the pipe 85, and by pipe 96 to the receiving chamber 84, and any over-flow to such stand-. 7 pipe is lead back to reservoir R through pipe 96.

By means of the circulating system, it will be obvious that any desired amount ofheated oil may be supplied to the different apparatus to be heated, or the oil'alone may be heated by opening valve 93 which brings about a short circuit of the circulating system. Also if'desired. pump P may be operated at such speed that oil is continuously forced into the reservoir and pumped therefrom, thus making thereservoir a part of the circulating system.

Power for the pump P may be supplied from motor M, which drives a shaft 74 by means of a belt 74 and pulley 75, shaft 74 driving the pum through belt 79 and pulley 80. Worm shaft 78, which operates the conveyor, may also .be driven from shaft 74 by means of belt 76 and pulley 77 If cooling water under pressure is not otherwise readily ayailable, a water pump 98 may also be driven from shaft 7 4 through pulley 98 and belt 99.

In purifying camphor according to the method of operation which is preferably followed with the above described apparatus, crude camphor is fed into baking chambers 1 through covers 4, and the chambers closed.

Slufiicient heat is a lied b means of the casing 32 until it is finall delivered at cutoil circulating s st i ii aliov e described, to let opening 37. The spiial blades ot the vaporize the cru e camphor, .with valves '10 conveyors 34, being staggered, rotate-1n such closed. -The heating in confinement is pre'fa manner that the blades of one conveyor erably continued until substantially all the will always clear the blades of the other, camphor oils and resinous products conso that each blade acts to scrape out the tained in the crude camphor are decomspaces between the turns of the other blade. posed, and converted into relatively-non- In this manner the camphor fumes are volatile substances, or, at least, into subchanged from a gaseous to a solid state, durstances having different volatility from caming all of which time the camphor is being 7 phor. At atmospheric pressure, camphor transferred from the entrance end of the melts at approximately 350 F., and boils at condenser toward the delivery end thereof. about 400 F., and a temperature of about ile we have describeda specific form 500 F., will convert the camphor into vaof our invention, It IS obvious that many por form without decomposing it or alterchanges will be made, which will stlll be 'mg it chemically, and such temperature it within the spirit thereof as defined in the maintained for approximately one hour is following claims. sufficient to decompose the above mentioned e claim:

. impurities. If-desired, the water may be re- 1. The method of purifying camphor moved at this time by inserting into the which comprises vaporizing camphor from baking chamber such material as lime. It the crude product, passing the resultin will be obvious that any desired number of fumes through liquid camphor, and cooling the-baking chambers may be utilized in perthe fumes to condensation. forming the heating operation with the 2. The method of purifying camphor valve 10 closed, while otherbaking chamwhich comprises passing camphor fumes bers may be either inoperative or performthrough liquid camphor, cooling said fumes ing the subsequent distilling operation. to condensation, and removing the solid cam- After t e organic impurities have been phor from the condensing chamber as it is above described, valves 10 and 12 are 3. The method of purifying cam'phor opened, so that the camphor vapors or fumes which comprises confining and heating the pass through header 8, pipe 9 into purifier crude product to a temperature sufiicient to 2. p In this latter member the fumes are comvaporize the camphor fromsame and de- 'pelled to pass through a body of liquid, such compose organic impurities, and cooling the as molten camphor, as above described confumes to condensation. m0 tained in troughs 16*; and this scrubbing op- 4. The method of purifying, camphor eration removes such foreign matter, as dirt which compiises' confining and heating the or dust etc, which may have become mecrude product to a temperature suilicient to chanicallymixed with the camphor fumes. vaporize the camphor from same and dee'organic impurities having been left becompose organic impurities, scrubbing the bind and thereby removed in the baking fumes by passing them through aliquid, and

chamber, and the camphor also having been coolin the fumes to condensation. purified as above described in the purifier 2, 1 5. Tie method of purifyin camphor substantially pure camphor fumes will pass w ich comprises confining and heating the through outlet 14 and pipe 26, which fumes crude product to a temperature sufficient to are in condition to be condensed and collected. vaporize the camphor from same' and de- If the preliminary cooler'30 is employed compose organic impurities, passing the the fumes will next be led through it, and fumes through liquid camphor, and cooling their temperature reduced thereby, alter the said fumes to condensation which they pass through opening 31 tothe 6. The method of purifyin camphor interior of condenser casing 32. At this which comprises confining and eating the point it is probable that the camphor might crude camphor to a vaporizing temperature be observed both in vapor and liquid form, and maintaining the temperature long and owing to the cooling of the condenser enough to decompose the impurities in the casing, condensation of the camphor upon crude camphor, scrubbing the camphor v away from the cooling surfaces, and at'the the walls thereof soon will take place. Such fumes through liquid camphor, and concondensation is assisted by the provision or. densing them while conti'nously removing the spiral blades which form an elongated the condensate. I passageway through which anyfumes must In testimony that they claim the foregoing pass in being led through the casing, wherethey have hereunto set their hands. by the blades hold the'camphor back, and JASPER E. CRANE. cause it to condense readily. 'As the cam EVARTS G. LOOMIS. phor solidifies the spiral blades scrape it Witnesses as to Jasper E. Crane:

STRICKLAND, same time convey it continuously through Ana Sonwmmrz. 

